During a shooting or launching stage of a nail gun among conventional power tools, a firing pin passes dynamic energy to a nail such that the nail is stuck into a workpiece from the surface of the workpiece. After completed in shooting, the firing pin has to be moved back to a start position and waits for a next shooting. However, in the process of retracting the firing pin as known in conventional nail guns, the firing pin often cannot be moved right back to the start position due to inappropriate internal structural design or suffering from external forces. Such nail guns often cannot achieve expected power and effect on the next shooting and thus the operation of nail shooting is affected.
It has been disclosed a conventional nail driving tool in Taiwan Patent Publication No. 200932442. The nail driving tool includes a lifter member, a latch member, and a driver member. The driver member has a first protrusion and a second protrusion disposed at two opposite sides thereof. The lifter member and the latch member are arranged corresponding to the two sides of the driver member, respectively. The first protrusion is driven by the lifter member such that the driver member is moved from a shooting position to a preparing position. During the lifter member moves the driver member, the second protrusion at the opposite side is captured by the latch member.
As for mechanical element design, the driver member has uneven overall thickness duo to the protrusions fabricated at the two sides thereof, and thus is weak in strength, easy to be damaged, and high in manufacturing cost. As for operational performance, the driver member may suffer from a great deal of deformation during the heating process and this may probably result in size mismatches between various components, thereby leading the operations to be more unstable. As for lifetime, the lifter member is directly driven by an electric motor, and the electric motor may have a short lifetime since the loading in activating the electric motor is large.